Detergent composition



UNITED STATES Ul USS HBIUIBHUU PATENT: OFFICE DETERGENT COMPOSITION William Beach Pratt, Boston, Mass: Annette Harris Pratt, administratrix of said William Beach Pratt, deceased No Drawing.

Application July 18, 1938,

Serial No. 219,824

9 Claims.

My invention relates to improvements in detergent compositions and are set forth in part in my Letters Patent of the United States No. 2,126,809, issued August 16, 1938, whereof the present application is a continuation in part.

As set forth in my said application, an embodiment of my invention comprises a dry neutral soap, an aldehyde and a dry oxidizing agent capable of oxidizing the aldehyde in the presence of moisture. Commercial soaps may be efiectively neutralized in the presence of carbon dioxide and thereby rendered suitable for use in conjunction with the aldehyde treatment without danger of forming condensation products. An aldehyde treatment may be effected by the use of formalin, or by dissolving paraformaldehyde or by the volatilization of trioxymethylene, or acetal or methylal. The oxidizing agent may be a perborate, such as sodium perborate. The ingredients are combined to form a readily soluble powder.

The soap, such as a neutral stearic acid soap in powdered form, has the formaldehyde uniformly distributed therethrough preferably in the form of trioxymethylene or formalin. The formaldehyde is thereby uniformly occluded in the soap and when ultimately oxidized by the admixture of the oxidizing agent forms in situ in the soap uniformly distributed minute quantities of formic acid having a strongly acid effect on I the pH value of the composition without precipitating the soap.

I find it generally desirable tg oxidize g agid the formaldehyde dispersed in the soap by dispersing hydrogen peroxide throughout the compgsi ti on. Satisfactory oxidation results also from blowing air through the soap and formaldehyde composition, or by dispersing sodium perborate or other active oxidizing agent therein. The moisture content of even redried neutral soap is sufiicient to facilitate the oxidation of the formaldehyde when trioxymethylene is used and the. water content of formalin solution or aqueous hydrogen peroxide solution also assists in the reaction when these ingredients are used.

The oxidation of the formaldehyde to acid results in the evolution of considerable heat and the temperature of the composition is so controlled as not to exceed about 120 F.

When the formaldehyde has been thoroughly oxidized, the composition has a very low pH value,

viz. 8.4-8 .8 when dissolved in water, and prolonged boiling of the solution results in a still lower pH value. This is contrary to the condition resulting from boiling in water any other soap preparation known to me. The low pH value characteristic of this composition renders it particularly valuable for use in hard water and for treating nitrogenous fibres. Such characteristic further renders practicable the admixture of considerable quantities of sodium perborate, or similar oxidizing agents, with the composition; retards excessive rapidity of liberation of oxygen from such agents by water; and prevent precipitation of the soap or other deleterious efiects from the caustic soda formed during the liberation of oxygen from sodium perborate.

For general use, I therefore admix f 1ge sg di ug perborate in the composition. This may be added as an excess of perfiorate when perborate is used to oxidize the formaldehyde, but is preferably added after oxidation of the formaldehyde has been completed by hydrogen peroxide or air. Care should be taken that the soap-formaldehyde composition is devoid of any reagents free to form condensation products with formaldehyde or combine therewith so as to prevent or retard oxidation thereof to acid.

The proportions of ingredients used may vary considerably. As an example of the practice of my invention, the following may be taken as illustrative.

Mix in a suitable mixer, such a a standard flour mixer, a neutral soap, regardless of the titer, and trioxymethylene, para-formaldehyde, or a 37% commercial aqueous solution of formaldehyde in a proportion equivalent to 2% of the actual aldehyde gas, figured as formaldehyde on the weight of the soap. After the soap and formaldehyde have been thoroughly mixed, an ai r addition to the use of the air blast for oxidizm' g the aldehyde, I may add to the soap-aldehyde mass--a small amount of hundred volume hy"- drogen peroxide solutionsay 2% by weight of the soap aldehyde mass. The hydrogen peroxide is preferably sprayed into the mixer as a fine spray. By the addition of hydrogen peroxide, the

t1me required for the oxidation of the aldehyde Examiner 2,279,248

may be materially reduced, and complete oxidation of the aldehyde may be effected in ten minutes, or even less.

In lieu of hydrogen peroxide, sodium perborate (preferably about 3%) or other oxidizer suitable for oxidizing aldehyde, may be intimately mixed modifications which may be made in detergent compositions based on soap modified by aldehyde oxidized in situ in the soap, I have added to such composition approximately 55% by weight of sodium perborate and approximately 60% by weight of borax. The sodium perborate and borax are added together to the aldehyde treated soap. Such borax further assists in lowering the pH value of the product and assists in taking up, by converting into mono-borate, any caustic soda that might be liberated from the soap or from the oxidation of the perborate after prolonged boiling in aqua solution.

As set forth in my previous application, a further embodiment of my invention may comprise a composition of neutral soap, aldehyde, sodium perborate and ammonia. Such a composition may be formed by adding to, say 50 parts by weight of water, one part by weight of neutral soap, one part by weight of aldehyde, six parts by weight of ammonia (26 Baum aqueous ammonia), and one part of sodium perborate, or other suitable oxidizing agent.

Having described my invention, I claim:

1. A readily water-soluble dry detergent composition which is stable when dry comprising a water-soluble alkali metal fatty acid soap having occluded therein minute particles of formic acid forming in the aggregate a minor proportion by weight of the composition, such formic acid not substantially exceeding the weight of formic acid resulting from oxidation to acid of a weight of formaldehyde equal to 2% of the weight of the soap and being insufllcient in amount to precipitate the soap but sufficient in amount relative to the soap to at least measurably lower the pH value of an aqeous solution of the composition below the pH value of an aqueous solution of such soap alone when both aqueous solutions are of like concentration, said composition being devoid of formaldehyde and of free alkali.

2. A readily water-soluble detergent composition which is stable when dry comprising a water-soluble alkali metal fatty acid soap having occluded therein minute particles of formic acid forming in the aggregate a minor proportion by weight of the composition, said formic acid being sumcient in amount proportionately to the soap at least to lower the pH value of an aqueous solution of the composition to approximately 8.8 but not substantially more than the amount of formic acid resulting from the oxidation to acid of a weight of formaldehyde equal to 2% of the weight of the soap; said composition being substantially devoid of formaldehyde.

3. A readily water-soluble stable homogeneous detergent composition comprising a detergent of the group consisting of borax and sodium per borate and a water-soluble alkali metal fatty acid soap having occluded therein minute particles of formic acid forming a minor portion by weight of the composition, said formic acid not substantially exceeding the weight of formic acid resulting from oxidation to acid of a weight of formaldehyde equal to 2% of the weight of the soap and being insuflicient in amount in the aggregate to precipitate the soap but suflicient in amount relative to the soap to at least measurably lower the pH value of an aqueous solution of the composition below the pH value of an aqueous solution of the soap alone when both aqueous solutions are of like concentration; said composition being devoid of formaldehyde.

4. The method of forming a readily watersoluble' detergent composition which is stable when dry, which comprises forming an intimate mix of a water-soluble alkali metal fatty acid soap and formaldehyde and occluding such formaldehyde in minute particles in the soap in minor proportion by weight thereto, and oxidizing the occluded formaldehyde by reaction under oxidizing conditions between the formaldehyde and an oxidizing annt comprising hydrogen peroxide and at a rate sufficient to completely eliminate the smell of formaldehyde from the mix within a few hours: the amounts of soap, formaldehyde and oxidizing agent being so proportioned to one another as to completely oxidize all the formaldehyde and cause suilicient heat of reaction during the elimination of the formaldehyde smell to substantially raise the temperature of the mix and form a reaction product from the formaldehyde and oxidizing agent suflicient in amount to measurably lower the pH value of an aqueous solution of the detergent composition below the pH value of a solution of soap alone when both solutions are of like concentration, but the quantity of such reagent being insufllcient to insolubilize the soap.

5. The method of forming a. readily water-soluble detergent composition which is stable when dry, which comprises forming an intimate mix of a water-soluble alkali metal fatty acid soap and formaldehyde and occluding such formaldehyde in minute particles in the soap in minor proportion by weight thereto; and oxidizing the occluded' formaldehyde by re-action under oxidizing conditions between the formaldehyde and an oxidizing agent comprising sodium perborate and at a rate suflicient to completely eliminate the smell of formaldehyde from the mix within a few hours: the amounts of soap formaldehyde and oxidizing agent being so proportioned to one another as to completely oxidize all the formaldehyde and cause suflicient heat of reaction during the elimination of the formaldehyde smell to substantially raise the temperature of the mix and form a reaction product from the formaldeh-yde' and oxidizing agent sufilcient in amount to measurably lower the pH value of an aqueous solution of the detergent composition below the pH value" of asolution of soap alone when both solutions are of like concentration, but the quantity of such reagent being insuflicient to insolubillze the soap.

8. The method of forming a readily watersoluble detergent composition which is stable when dry, which comprises forming an intimate mix of a water-soluble alkali nietal fatty acid soap and formaldehyde and occluding such formaldehyde in minute particles inthe soap in minor proportion by weight thereto, and oxidizing the occluded formaldehyde by reaction under oxidiz LAGHHHCI ing conditions between the formaldehyde and an oxidizing agent comprising air; such air being blown through the mix at a rate suflicient to completely eliminate the smell of formaldehyde from the mix within a few hours: the amounts of soap, formaldehyde and oxidizing agent being so proportioned to one another as to completely oxidize all the formaldehyde and cause suflicient heat of reaction during the elimination of the formaldehyde smell to substantially raise the temperature of the mix and form a reaction product from the formaldehyde and oxidizing agent sufiicient in amount to measurably lower the pH value of an aqueous solution of the detergent composition below the pH value of a solution of soap alone when both solutions are of like concentration, but the quantity of such reagent being insufllcient to insolubilize the soap.

7. The method of forming a readily watersoluble detergent composition which is stable when dry, which comprises forming an intimate mix of a water-soluble alkali metal fatty acid soap and formaldehyde and occluding such formaldehyde in minute particles in the soap in minor proportion by weight thereto, and oxidizing the occluded formaldehyde by reaction between the formaldehyde and a non-acid oxidizing agent devoid of residues deleterious to detergency and at a rate suflicient to completely eliminate the smell of formaldehyde from the mix within a few hours: the amounts of soap, formaldehyde and oxidizing agent being so proportioned to one another as to completely oxidize all the formaldehyde and cause suilicient heat of reaction during the elimination of the formaldehyde smell to substantially raise the temperature of the mix and form a reaction product from the formaldehyde and oxidizing agent sufflcient in amount to measurably lower the pH value of an aqueous solution of the detergent composition below the pH value of a solution of soap alone when both solutions are of like concentration, but the quantity of such reagent being insufficient to insolubilize the soap.

8. The method of forming a readily watersoluble detergent composition which is stable am-d;

when dry, which comprises forming an intimate mix of a water-soluble alkali metal fatty acid soap and formaldehyde and occluding such formaldehyde in minute particles in the soap in minor proportion by weight thereto, and oxidizing the .occluded formaldehyde by reaction under oxidizing conditions between the formaldehyde and an oxidizing agent of the group consisting of hydrogen peroxide, sodium perborate and air and at a rate suflicient to completely eliminate the smell of formaldehyde from the mix within a few hours: the amounts of soap, formaldehyde and oxidizing agent being so proportioned to one another as to completely oxidize all the formaldehyde and cause suflicient heat of reaction during the elimination of the formaldehyde smell to substantially raise the temperature of the mix and form a reaction product from the formaldehyde and oxidizing agent suificient in amount to measurably lower the pH value of an aqueous solution of the detergent composition below the pH value of a solution of soap alone when both solutions are of like concentration, but the quantity of such reagent being insuilicient to precipitate the soap.

9. The method of forming a readily soluble water detergent composition which is stable when dry, which comprises forming an intimate mix of a water-soluble alkali metal fatty acid soap and trioxymethylene in minor proportion by weight to the soap, said trioxymethylene being capable of evolving formaldehyde, spraying into the mix under oxidizing conditions hydrogen peroxide in amount in minor proportion to the weight of the mix sufficient to completely oxidize to acid all formaldehyde evolved by the trioxymethylene included in the mix, agitating the mix sufficiently to efiect complete reaction between the hydrogen peroxide and all formaldehyde evolved from trioxymethylene within a few minutes and at a rate suflicient to materially heat the mix, and combining with the heated mix a detergent of the group consisting of borax and sodium perborate and forming thereby a BEACH PRA T 

